Thanks for the question, great troubleshooting so far.
To isolate further, does the issue persist in a new user account? If so, follow these steps:
When troubleshooting system-wide issues with iTunes, there are a few different suggestion to try.
Check for viruses
Windows viruses can interfere with a variety of computer functions including iTunes. Make sure that you have current anti-virus software installed with updated virus definitions and use it to scan your system.
Check for anti-virus and/or Internet security software
Internet Security software itself can sometimes cause iTunes to quit unexpectedly. Try disabling the Internet Security software temporarily or exempting iTunes from any active scanning done by such software. If this resolves the issue, check with the maker of the software for an update to the software or its virus definitions. See the following article for more information: iTunes for Windows: Troubleshooting security software issues.
Sometimes other programs and startup items can conflict with iTunes, look at the following article to troubleshoot such conflicts:
Removing iTunes configuration files
Removing unusable configuration files that iTunes uses can resolve launch issues. See "iTunes for Windows Vista or Windows 7 doesn't open after upgrading" for information.
Check the iTunes and QuickTime installations
An improper installation of iTunes or QuickTime can contribute to a variety of issues. Follow the article below to learn how to completely reinstall iTunes and QuickTime:
Update the drivers on your PC
Having outdated drivers on your computer can cause strange behavior with iTunes, QuickTime, iPod, and other applications. See this link to update the drivers on your computer.